what is the special feature of the upper mantle

The upper mantle is the layer of rock inside the Earth that begins just beneath the crust and extends to a depth of about 410 kilometers (255 miles) . It is divided into two regions: the lithosphere and the asthenosphere. The lithosphere is the solid, outer part of Earth, extending to a depth of about 100 kilometers (62 miles), and includes both the crust and the brittle upper portion of the mantle. The asthenosphere is located just below the lithosphere and is made up of rock that is fluid and capable of flowing. The special feature of the upper mantle is the asthenosphere, which is more malleable than the rest of the upper mantle and contributes to tectonic activity.